Side arm heater



Aug. 20, 1946" c. E.' wnLlG -SIDE ARM HEATER Filed'Feb. 19, 1945 IN VEN TOR.

A TTOPNEYS Patented Aug. 20, 1946 UNITED STATES PATET SIDE ARM HEATER Celestn Eugene Willig, Buffalo, N. Y.

Application February 19, 1945, Serial No. 578,781

2 Claims. l

This invention relates to a side arm Water heater, such water heaters being used in connection with a domestic water tank to heat the `water in the tank by convection, the water being withdrawn from the lower part of the tank and upon being heated in the heater rising and being returned to the upper part of the tank so as to effect a recirculation and heating of the body of water in the tank.

One of the principal objects of the present invention is to provide such a side arm water heater, heated by gas, in which provision is made for long narrow flue travel of the gas and to provide such a heater in which the maximum amount of gas is brought in contact with the water coil to obtain the maximum amount of heated water.

Another object is to provide such a water heater which is compact and at the same time has a large amount of water tube surface and has high heat transfer efficiency.

Another object is to provide such a side arm water heater, heated by gas, in which dead or useless space is avoided andV in which flame spreaders and the like are eliminated.

Another object of the invention is to provide such a heater in which the ame does not contact the coil thereby to increase the life of the coil.

Another purpose is to provide such a heater having a straight flue and in which the use of baliies or the like is avoided.

Another purpose is to provide such a heater in which the water inlet and outlet are in axial alinement at the center of the heater thereby to permit of installing the side arm heater closer to the storage tank, to save space and to provide a side arm heater which is of pleasing appearance.

Another object is to provide such a side arm heater which can be readily provided in any size required.

A further object of the invention is to provide such a side arm heater which is easily installed, removed and reinstalled and in particular can receive'the gas supply pipe from any side so as to avoid the necessity of elaborate pipe tting.

A further object of the invention is to provide a simple sectional jacket which can be placed in position after all the piping connections have been made thereby to facilitate the installation of the heater as well as to permit ready removal, inspection, cleaning and repair.

A further object is to provide such a heater which can be manufactured and shipped in a disassembled condition so as to reduce Shipping space as well as to facilitate both the manufac-` ture and the installation of the heater.

Another object is to provide such a water heater in which pockets in the water line are avoided, thereby to prevent the accumulation of sediment and to insure the heater operating at high efciency for a long time.

Other objects and advantages will appear from' the following description in which:

Fig. 1 is a vertical section through a gas heated side arm water heater embodying the present invention and showing its water, gas and flue connections.

Fig. 2 is an enlarged horizontal sectional View, taken on line 2--2, Fig. 1.

Figs. 3 and 4 are horizontal sections, taken on the correspondingly numbered lines of Fig. 1.

The side arm heater embodying the present invention includes a water coil indicated generally at l and housed within a sectional jacket, indicated generally at 2, the gas being supplied` to a burner 3 at the bottom of the casing 2 and the products of combustion passing out from the upper end of the casing 2 through a flue fl. The coil l is preferably made of copper and includes a central vertical tube 5 o f substantially greater diameter'than the water inlet and outlet pipes 6, 8, the central tube 5 being reduced at its lower end and swaged to the water inlet pipe 6 and being similarly reduced at its upper end and swaged to the Water outlet pipe 8. It will be understood that the water inlet pipe 6 connects with the lower end of the water storage tank (not shown) and that the water outlet pipe 3 connects with the upper end of this water storage tank so that the water, upon being heated and traversing the coil l, will rise and effect a recirculation of the water through the water storage tank.

To the lower end of the enlarged central tube 5 of the water coil is secured the lower end of a helical coil l0, the convolutions of this helical coil l0 surrounding the central tube 5 and being spaced therefrom so that the products of combustion from the heater 3 pass upwardly through the annular ue provided between the central tube 5 and the helical coil I0. The upper end of the helical coil I5) is secured and discharges into the upper end of the central tube 5.

It will therefore be seen that the water enter- I ing the coil l from the inlet pipe 6 passes upwardly in two parallel streams, one stream flowing through the central vertical tube 5 and the other stream flowing through the helical coil Ill. In order to balance the flow of the water through the heater so as to obtain approximately the same rate of ow in the central tube 5 as in the helical coil I0, baille means are preferably provided in the central tube 5. For this purpose a helically twisted strip of metal l2 is shown as arranged in the central tube 5, this being designed to provide resistance to approximately balance the greater resistance of the helical coil 5. It will also be seen that this twisted bale strip I2 provides increased turbulence and secures improved heat transfer efficiency. Further, to increase heat transfer efficiency and also to increase the surface area of the helical coil I with reference to the cross sectional area of this coil, this coilA 1 is preferably flattened instead of being circular in cross section.

In order to facilitate the connection with the gas supply pipe, the burner 3 is in the form of a horse-shoe shaped casting which permits it to be inserted under the coil l from any side and also permits it to be so inserted and removed after the coil has been connected with the inlet and outlet pipes 6, 8. 'I'his burner is Yprovided with the usual orices in its upper side Vfor the discharge of the fuel mixture and the burner is arranged so as to embrace the inlet pipe 6 immediately below the lower reduced end of the central vertical tube 5. The burning gas from the burner 3 thereby is discharged around the enlarged central tube which avoids the necessity of aflame spreader or the like, this gas passing vertically upward principally through the annular iiue space provided between the central `tube 5 and the surrounding helical coil lll. The burner 3 connects by a pipe l5 with amixing valve i6, the gas supply line being indicated at I8.

After the water and gas connections have been made the casing 2 can be Vassembled around the burner 3 and coil I. For this purpose the casing is shown as including a tubular sheet metal shell which can be longitudinally split, as indicated at 2l, or made in two separate pieces so as to permit of its application around the coil i after it has been installed. At its upper end this tubular shell 20 is embraced by the two halves of an upper end head 22, this end head having a cylindrical side wall which embraces the upper end of the shell 20 and is formed to provide the flue 4, and this end head also having an end wall which is provided with a hole receiving the pipe 8. To secure the two halves of the upper end head 22 together, to each half of this end head is riveted, or otherwise suitably secured, a half section of a collar 23. This'collar has an upstanding tubular portion 24 which embraces the pipe 8 and to secure the two halves of the collar together each half is provided with a pair of flanges 25 through which bolts or other suitable fastenings 26 extend. A similar bottom end head 28 is provided, this bottom end head being formed intwo halves and secured together by a two part collar 29 which is similar to the collar 23V and the halves' be completely installed before the unit is encased. This greatly facilitates installation, particularly as Athe gas pipe l 5 can come in from any side and also does not have to be placed with a high degree of accuracy since the horse-shoe shaped burner permits considerable latitude in locating the burner. After the piping is completed the casing is applied, this merely requiring the wraping around of the shell 20, the application of the two part end .heads 22 and 28 and tightening the bolts 26.

From the foregoing it will be seen that the present invention provides a coil for a side arm heater which is free from sediment pockets; is compact; and has high heat transfer efficiency, particularly in the passing of the water in parallel through the central tube 5 and the helical tube I0, the two forming a straight ue exposing a large amount of surface to the heated gas. Further, the provision of baies or flame spreaders is unnecessary and the coi1 is also protected against injury from the flame of the burner. The heater is also readily installed and provides c, an attractive side arm heater.

Y tube, a second water tube of smaller 'diameter than said central tube and having a series of convolutions surrounding said central tube 'in spaced relation thereto and generally concentric therewith, means connecting the upper and lower ends of said second water tube with the upper and lower ends, respectively, of said central tube whereby the water flows upwardly through said two water tubes in parallel, and a helically twisted ribbon in and extending substantially the full length of said central 7tube and impeding the ilow of Water therethrough thereby to divert an increased proportion of water through said second water tube.

2. In a side arm water heater, a coil assembly comprising a substantially straight vertical central water tube of relatively large diameter, a water inlet pipe of smaller diameter than said central tube extending axially from the lower end of said central tube, a water outlet pipe of smaller diameter than said central tube extending axially from the upper end of said central tube, a second water tube of smaller diameter than said central tube and having a series of convolutions surrounding said central tube in spaced relation thereto and generally concentric therewith to provide an annular vertical flue between said tubes, and means connecting the upper and lower `ends of said second water tube with the upper and lower ends, respectively, of said central tube whereby the water flows upwardly through said two water tubes in parallel,- and a U-shaped gas burner having horizontal legs connected at one end only and embracing said water inlet pipe below said central tube and discharging burning gas to flowupwa'rdly through said annular flue in contact with both of said; tubes. t CELES'I'IN EUGENE WILLIG. i 

